Research

Knee protection for female footballers

Female football players are afflicted by cruciate ligament injuries more than twice as often as men. Teenage girls are especially vulnerable. A short warm-up programme before each training session can significantly reduce the risk of injury, according to an extensive study at Linköping University.

“The plank” is one of the exercises of a preventive workout regime that increases players’ control of their knees.

More than 4,500 players, girls aged between 12 and 17, took part in the study, the results of which have now been published in the distinguished British Medical Journal (BMJ). A team of researchers led by Martin Hägglund (pictured) and Markus Waldén, researchers in physiotherapy and community medicine respectively, has shown that the risk of an anterior cruciate ligament injury was reduced by two thirds for players who performed a 15 minute-long neuromuscular exercise session a couple of times a week.

Damage to the anterior cruciate ligament is one of the most serious knee injuries. It requires long-term rehabilitation and can cause the early onset of arthritis.

In order to test the merit of preventive neuromuscular exercise, the Linköping researchers invited 230 football clubs in southern and central Sweden to take part in an intervention study. The trainers at 121 of the clubs were instructed to lead two sessions a week, consisting of five minutes of jogging followed by six exercises during a total of 15 minutes. 109 clubs made up a control group where there were no preventive exercise sessions.

“The focus is on achieving good control of the foot, knee and hip, to avoid the knees ‘buckling inwards’ when weight is put on the bent knee. It is this kind of situation that causes most anterior cruciate ligament injuries,” says Hägglund.

Physiotherapists and doctors assisted the trainers during the study, which took place during the 2009 football season. A total of 96 knee injuries occurred, evenly distributed between the two groups. Anterior cruciate ligament injuries affected 7 girls from the intervention group compared to 14 in the control group. The players in the clubs who carried out the training sessions had 64 % fewer injuries of this kind than the players in the control group.

However, not all of the players in the intervention group followed the training programme. When the results were examined in detail, it turned out that the players who performed the training sessions at least once a week throughout the entire season had 83 % fewer anterior cruciate ligament injuries.

“This is a very high number, and it shows the importance of good flexibility in preventing injury. These girls also had fewer serious knee injuries in general,” says Hägglund.

A follow-up study of all of the teams is now planned, with the purpose of assessing whether the training programme is still followed. The Swedish Football Association has also started to implement the programme on a large scale.